- 1 Amazon best sellers
- 2 Ultra-budget gaming PC
- 3 Computer form factor comparison
- 4 Intel Processor
- 5 Graphics
- 6 SoC
- 7 Low end PC/tablet and Chromebox
- 8 Projectors
- 9 M.2
- 10 Hard disk
- 11 SSD
- 12 UFS, eMMC, SSD
- 13 MicroSD card
- 14 USB device speed comparison
- 15 MemTest86
- 16 ATX 24pin power supply
- 17 Blu-ray Drive
- 18 Nintendo Devices hack
- 19 How to silence your computer mouse
- 20 Cellular phone
- 21 FLIRC FL-09028 USB Universal Remote Control Receiver
- 22 Vehicle camera recorder
- 23 Mirrorless & DSLR cameras
- 24 HDMI & CEC
- 25 Google Chromecast
- 26 Amazon Echo
- 27 Amazon Fire TV
- 28 Amazon Kindle ebook reader
- 29 Amazon Kindle Fire Tablet
- 30 Live TV
- 31 Cordless Phone
- 32 Headphone
- 33 Microphone
- 34 You Really Can Charge Your Phone With a 9 Volt Battery
- 35 USB voltage meter
- 36 Kill A Watt P3
- 37 Best printers
- 38 Laser Engraving Machine
- 39 Make your own laptop screen for Raspberry Pi
- 40 E-ink
- 41 Boox Note Plus
- 42 ONYX BOOX Max Carta
- 42.1 Onyx Boox Max Carta vs Onyx Boox MAX2
- 42.2 Boox as a Second Monitor
- 42.3 Boox and SSH terminal
- 42.4 Airdroid
- 42.5 Boox and remote desktop
- 42.6 Open html files
- 42.7 Open epub files
- 42.8 Open pdf files
- 42.9 Note
- 42.10 Music
- 42.11 Settings
- 42.12 Android apps
- 43 Kobo ereader
- 44 Flexible E-ink
- 45 Power over Ethernet (PoE)
- 46 USB
- 47 How to Crimp Your Own Custom Ethernet Cables of Any Length
- 48 Wake-on LAN
- 49 How to park your car on a hill
- 50 Roku
- 51 Router
- 52 Wifi and health
- 53 Logitech Unifying Software
- 54 Bluetooth adapter
- 55 Best bluetooth mouse
- 56 Mouse Acceleration vs Sensitivity
- 57 Keyboards
- 58 Webcam
- 59 Qmote
- 60 How to Replace an Outlet That’s Controlled by a Light Switch
- 61 How to Ship Packages Without Leaving Your House
- 62 Photos
- 63 Drone
- 64 Screws size
- 65 Desk
- 66 Dell PowerEdge R630 server
- 67 iPad 9.7 2017 (5th)
- 68 Notebook
- 69 Laptop battery
- 70 Battery Life
- 71 Watch battery
- 72 CR2032 battery
- 73 Homopolar motor
- 74 Govee Wi-Fi Temperature and Humidity Monitor
- 75 Google voice & Obihai
- 76 Burr coffee grinder
- 77 Shopping
- 78 How to Spruce Up Your Office Desk
Amazon best sellers
Ultra-budget gaming PC
Computer form factor comparison
- Standard ATX > Micro ATX > Mini ITX > Nano ITX > Pico ITX
- No Ethernet port
- Can get very HOT
- No Audio out jack
- Does not use opensource chipsets for wifi/bluetooth.
- F2: boot into BIOS
- How to find Intel NUC BIOS version and model on Linux
- Ubuntu 16.04 LTS certified for Intel NUC for IoT device development 6/26/2018
- (Mine) 1.5 GHz Intel Pentium J5005 Quad-Core, NUC7PJYH, 1 x 2.5" Drive Bay. Intel website 1 & website 2. Review by nucblog.net. Youtube review.
- Wake up from suspend using wireless USB keyboard or mouse (for any Linux Distro) (not working yet)
ODroid-H2 (Intel Celeron J4105 Gemini Lake processor, 2018) $111
- Intel Celeron J4105 vs. Intel Pentium J5005
UDOO x86 PENTIUM N3710 (ultra), CELERON N3160 (advanced) 2016.
- Atom: Bay trail, Cherry trail, ...
- Skylake (sixth-generation Core series of processors) and review
- Intel's New Core M CPU: Everything You Need to Know
- Apollo lake replacing Braswell for low-power laptop/netbook/cloudbook.
Y series vs U series
stats for nerd in Youtube
My own collection of SoC
|Device||Family||Instruction||Clock & Memory|
|Raspberry Pi||ARM11||ARMv6||700MHz, 512MB|
|Beaglebone Black||Cortex A8||ARMv7||1GHz, 512MB|
|UDOO||Cortex A9||ARMv7||1GHz, 1GB|
|Odroid Xu4||A15 & A7||ARMv7||2GHz & 1.4GHz, 2GB|
Comparison of single board computers from Wikipedia
from Adafruit. It includes spec comparison, performance test, power usage, ...
- Arduino motor spin
- Arduino Uno vs Beaglebone vs Raspberry Pi from Makezine.com.
- Arduino Uno vs Raspberry Pi vs Beaglebone black from lifehacker.com.
Low end PC/tablet and Chromebox
Intel® Atom™ Z2760, 2G ram, 64GB storage and Micro-HDMI.
Lenovo chromebook S330
Intel Celeron 2955U Processor 1.4 GHz, 2GB DDR3 RAM, 16GB ssd, Year 2014
It is not updated for the meltdown & spectre bug. See this list.
To enter the developer mode, use the 'reset' button (a small hole next to Kensington lock). See
- Developer mode chromebox in HP chromebox
To invoke developer/recovery mode, you insert a paper clip and press the RESET BUTTON (just beside the kensington lock) and press the Power button. Release the RESET BUTTON after a second.
To enter Dev-mode you first invoke Recovery, and at the Recovery screen press Ctrl-D (there's no prompt - you have to know to do it). It will ask you to confirm by pressing the reset BUTTON again.
Dev-mode works the same as always: It will show the scary boot screen and you need to press Ctrl-D or wait 30 seconds to continue booting.
It seems the 'Reset' button is called 'Recovery' button on ASUS chromebox. See here.
See Gallium OS.
- Upgrade the RAM.
- M2 SSD (22mm x 42mm). Transcend 256GB SATA III 6Gb/s MTS400 42 mm
- Taken apart Video
ASUS website. 1.7 GHz Intel Core i3-4010U Processor, 4GB of 1600 MHz DDR3 RAM, 16GB Solid State Drive, Year 2014
A newer one is CN62.
Both are not updated for the meltdown & spectre bug. See this list.
ASUS chromebook C423
Intel® Atom™ Z3735G Quad Core (64-bit), 1G ram, 32GB storage. The C: drive shows the space is 23.5 GB. The free space is 20GB. After the first Windows update the storage space is reduced from 18.6 to 16.8. After running Disk cleanup utility, the storage now becomes 17.1 (still lose a lot). So the lesson is not to run Windows update if the disk space is very limited (eg tablet) & everything is working fine now.
- X2 using Intel® Braswell N3050 SOC
- X using Intel® Bay Trail-M/Bay Trail-I SOC (N2808). For?reason, it won't be shipped to my area from newegg.
Low cost laptop
Best Chromebooks That Run Android Apps
- Macbook Pro 2015- 4lb 6.9oz
- Lenovo Thinkpad T420s - 4lb 1.0oz, removing DVD - 3lb 12.7oz
- Lenovo Thinkpad T440s - 3lb, 7.4oz. Touchpad design makes cursor jumps when clicking.
- Lenovo Thinkpad E480- 3.85lb
- Lenovo Thinkpad X1 carbon (6th gen)- 2.49lbs
- Lenovo Thinkpad 13 Chromebook (usb-c) - 3.2lbs
- Lenovo ThinkPad L390 - 3.2lbs (L-series for business customers)
- Lenovo Flex 14 81SS0005US - 3.52lbs
LED, 30 ANSI lumen 854x480, 12V & 1A power. The manual is available at Samsung web site here. The input signal in D-Sub can be 1280x800, 1280x768, 1280x720 resolution although the manual also said "All resolutions higher or lower than 854 x 480 are converted to 854 x 480 by the scaler chip in the projector. To obtain an optimal picture, the resolution from the PC should be similar to the projector (854 x 480)".
Vivitek Qumi Q5 500
- M2 SSD have two kinds. One is M2 + SATA and the other is M2 + PCIe + NVMe. https://youtu.be/alb6-zp52mA?t=159
- WD BLACK SN750 250GB NVMe Internal Gaming SSD - Gen3 PCIe, M.2 2280, 3D NAND - WDS250G3X0C
From 'best to worst' it goes MLC (such as Samsung 970 pro, 2x as expensive as similarly sized drives but also 2-3x faster), then TLC, followed by QLC.
- 5 Most Reliable Hard Drives According to Server Companies (11/30/2017)
- Western Digital Red - NAS application
- Toshiba MD04ABA400V
- HGST HUH728080ALE600
- Seagate ST8000DM002
- Western Digital Black - high performance
- A 7200 RPM drive presents minimal performance gains over a 5400 drive. Especially when compared to an SSD.
- Greens are for eco-oriented folks who want less power consumption
- Blues are your standard vanilla drives
- Reds are performance oriented drives that spin at variable rates
- Blacks are for enthusiasts willing to shell out a premium
Hard drive comparison
Hard drive docking station
- Sabrent USB 3.0 to SATA Hard Drive Docking Station w/ UASP (EC-DFLT). A firmware upgrade requires a Windows PC.
- https://www.sabrent.com/downloads/ Download from Sabrent. Search for "EC-DFLT".
- https://www.startech.com/Downloads. SATDOCKU3E.
2.5 inch SATA SSD and M.2 SSD
- What Is the M.2 Expansion Slot, and How Can I Use It?
- SanDisk 16GB
- MyDigitalSSD 128GB
- SATA 介面的效能約莫為 3 - 5 倍左右，而 PCIe NVMe 的效能表現更高，相較於 HDD 可達 10 - 30 倍的效能表現。 價格進入「甜蜜點」，現在入手 SSD 正是時候！選購 SSD 必備知識，效能 UP UP 的 SSD 升級實戰！
SATA 採用 B + M Key 的設計，而 PCIe 則為 M Key 設計，兩者並無法相容。
SLC, MLC, TLC, QLC
Your Next SSD Might Be Slower (Thanks to QLC Flash). In short, QLC SSDs Break Down Much Quicker. You should definitely avoid QLC drives with 512 GB and less. QLC flash isn’t too much of an issue when you look at the higher capacity drives.
UFS, eMMC, SSD
- http://www.howtogeek.com/293339/what-makes-emmc-flash-memory-viable-in-mobile-devices-but-not-pcs/ eMMC vs SSD. eMMC (NVRAM technology) has a write cycle of 3k to 10k but SSD (NAND or NOR technology) has a write cycle of 10k to 30k.
Maximize the lifetime
- Some helpful tips on extending the life of your card
- The MicroSD card should be reformatted every 2 weeks to maximize the lifetime of the memory card (from the manual of Vantrue N1 Pro Mini Dash Cam) .
- How often should memory cards be formatted?
- Formatting clears the directory structure of the card and removes any artifacts that might be left behind by erasing. Repeatedly using the ERASE and ERASE ALL camera options and not formatting can result in a buildup of file artifacts that may eventually cause the card to fail.
- How often does a microSD card needs to be formatted?
- While the quick format will simply clear the filesystem table so all the space on SD card will appear as available (the data is still on the card), the full format will also check for errors and remove all the data from the card by writing zeros (for example).
- MEMORY CARD BEST PRACTICES: 15 THINGS YOU SHOULD ALREADY BE DOING
- Formatting is a more complete way of clearing old files from your card and can reduce the risk of data corruption.
- How and Why Should I Reformat My Memory Card?
- Deleting or erasing a file doesn’t necessarily remove it. Instead, your card will simply write over the “deleted” files whenever you save new data. This means the “deleted” files remain on the card until they’ve been replaced. Reformatting is a more thorough security measure that ensures you permanently erase all the data before adding new files or images. It’s the only way to rest assured that a file is truly erased.
- https://havecamerawilltravel.com/photographer/fastest-microsd-cards/ (Updated Apr 2018)
- V60: 60MB/s
- V30: 30MB/s
- U3: 30MB/s
- U1: 10MB/s
- class 10: 10MB/s
- class 2,4,6: 2,4,6 MB/s
Best microSD card
USB device speed comparison
See http://www.elinux.org/RPi_SD_cards#Performance for an objective way to get write/read speed by using command line tool 'dd'.
|Patriot XT 32G USB3.0||Example||50MB/s||vfat|
|Patriot XT 32G USB3.0||Example||115MB/s||fat16|
|Patriot XT 32G USB3.0||Example||113MB/s||fat32|
|Patriot XT 32G USB3.0||Example||24MB/s||ntfs|
|Patriot XT 32G USB3.0||Example||139MB/s||ext2|
|Patriot XT 32G USB3.0||Example||50~100MB/s||ext3|
|Patriot XT 32G USB3.0||Example||140MB/s||ext4|
When testing Patriot XT USB 3.0 drive, I partition it into ext2 (15GB)& ext3(15GB). The problem of unstability in Patriot XT's ext3 partition is not related to ext3 partition because if I switch the order of partitions of ext2 and ext3, then ext2 becomes unstable.
- A word about USB flash drive.
- According to the Slo Bytes USB Flash Drives report from Brian K. Lewis, flash drives are capable of handling 10 thousand to 10 million write and erase operations during their lifetime, depending on the source as well as the specific USB drive. Regardless, a flash drive typically will outlast any standard hard drive. The main concerns about the life expectancy of a flash drive are damage from neglect and becoming lost or stolen.
- The life expectancy of a USB Flash Drive can be measured by the number of write or erase cycles. USB flash drives can withstand between 10,000 to 100,000 write/erase cycles, depending on the memory technology used. When the limit is reached, some portion of the memory may not function properly, leading to lost of data and corruption.
- Most experts would agree that around 10 years is about what you can expect to retain data on a flash drive without powering it up. That means you can lock away a USB drive for 10 years and return to still see your data. After 10 years of not being powered on, the electrical charges determining if bit of information is either a ‘1’ or a ‘0’ gets hazy. This is because like all electrically charged devices, they suffer from what is called electro/magnetic deterioration; or simply put, where devices will eventually lose their power.
- The copy-paste speed on my 7200rpm hard disk is about 160MB/s.
- Tested using Seagate portable drive SRD0SP0 500GB with USM((Universal Storage Module)/USB 3.0. When it is connected to USB 2.0/3.0, the writing (from an internal hd onto it) speed is at best 30MB/s. When it is connected to USB 3.0, the writing (from it to an internal hd) speed is at least 60MB/s.
- DIY USB on the go cables.
M2 NVMe to USB enclosure
- https://www.memtest86.com/technical.htm. It has a total 4 passes. Each pass has 13 tests. It could take over an hour to run 13 tests for one pass.
- How many tests needed to run for memtest86?
- If we have multiple memory modules/sticks, we can test them one by one.
Nintendo Devices hack
An easy way to take off the cape of the rectangle box is to use a pairs of long nose pliers instead of a knife. The method works on my Logitech M210 mouse. The trick is to shorten the click distance.
Cellular phone frequency list
- North America
- Cheat sheet: which 4G LTE bands do AT&T, Verizon, T-Mobile and Sprint use in the USA?
- 1700 (3G UMTS),
- 1900 (3.5G HSPA+),
- 2/4/12 (4G LTE)
Chunghwa telecom uses 2100 for 3G/3.5G.
What is the difference between G, E, 3G, H, H+ and 4G symbols? We find out!. The order is (from fastest to slowest)
Verizon, AT&T, T-Mobile, and Sprint: Which Mobile Carrier Is Best for You?
GSM vs CDMA
Mobile virtual network operator
- Mobile virtual network operator/Prepaid carriers
- The 7 Cheapest Prepaid/postpaid Phone Plans With Unlimited Everything
3 Ways to Find Free Unlocking Codes for Mobile Phones
How to Block Unknown Callers
Buy a phone
- Buying New vs. Used Smartphones: What’s the Cheaper Option?
- The Best Android Phones Under $300 Oct 2018
- The 6 Best Unlocked Phones Under $200 Oct 2018
- Nextbin Robin frequency bands and network compatibility
Vehicle camera recorder
1. night vision 2. can turn on/off manually 3. pictures stable (not flicker) 4. G-sensor 5. 3D turning on mount racket 6. no surprising things like auto turned off, (power, start) buttons not working, freeze 7. video space (640x480 takes 100MB for 1 min???). The Amazon website has a list of popular dash cams.
Mirrorless & DSLR cameras
Nikon D5600 camera
- BEST Video Settings To Record Video On ANY Nikon DSLR (D5200/D5300/D5500 FULL Tutorial)
- Nikon D5600 "User Guide": How To Setup Your New DSLR 36:58 long.
- Keep the lcd screen on the back display of your nikon dslr on for a longer time? Custom setting menu -> Auto off timers. Default 'norm' is 8 seconds and 'long' is 1 minute.
- Nikon D5600 Overview Tutorial 1:24:16 long.
- Got a new Nikon? Some cool camera tips for beginners 5:49 long.
- Lens Bag with Adjustable Drawstring
- How to Use Wi-Fi Transfer on Your Nikon D5500
Can anything be done to reduce the shutter sound on my SLR?
- What Focal Length Should I Use For My Photos?
- What Aperture Should I Use With My Camera?
- How to take portraits with blurred backgrounds
- Stand back a little and zoom-in your lens – this is related to focal length/angle of view/sensor size
- Choose the smallest f-number (bigger aperture) that’s available.
- increase the distance between the subject and the background
- How To Blur The Background With A Dslr
- Open the aperture wider for a more shallow depth of field
- Use a longer focal length (zooming in) to blur the background more
- Get closer to the subject for a macro effect
- How to Take a Photo With a Blurred Background Use a cell phone or small point-and-shoot camera
- Choose portrait mode, and turn off the flash.
- Make sure the subject is far from the background.
- Get close to your subject
- How to Take Great Photos with the Nikon D5600 from tom's guide.
- Taking Pictures of Fireworks, How to Photograph Fireworks
- Manual mode
- Use a wide or telephoto zoom lens
- Start with a slow shutter speed of 2.5-4 seconds
- Set the camera to a low ISO level (ISO 100) and a narrow aperture field (f/5.6-f/8 or bumping up to f/11-f/16)
- Understanding Metering and Metering Modes
- Exposure Bracketing: The Creative Insurance Policy
HDMI & CEC
CEC (Consumer Electronics Control) allows for control of devices over the HDMI port.
- How to Enable HDMI-CEC on Your TV, and Why You Should
- How to find out if your device is HDMI CEC capable?
micro HDMI vs mini HDMI
- Mini HDMI/Type C (flat, wider) is used on DSLR cameras standard sized tablets. Raspberry Pi zero.
- Micro HDMI/Type D (smallest) is used on smaller portable devices such as smartphones and smaller tablets. Raspberry Pi 4.
Amazon Fire TV
- Navigation with the remote.
- How to Cast YouTube and Other Web Videos to Kodi (Like the Chromecast)
- Kore (Android)
- Yatse (Android)
- Pushbullet (iOS & Android)
Bypass Google’s YouTube block on the Amazon Fire TV
Send to kindle web extraction failed when I tested 'Send to Kindle' from an iPad.
But it works when I use the Chrome extension on the Chrome browser.
To take screenshots, just hold down on on the top left and button right, or the top right and bottom left. The pictures are stored in the root folder of your Kindle Paperwhite. You can plug your e-reader into your PC via the USB cable and get access to any of the pictures you took.
Identify Kindle generation
https://www.amazonforum.com/help/identify-your-kindle-e-reader. Mine is paperwhite 7th generation released 2015.
Kindle Paperwhite 3 (2015, 7th generation) vs Paperwhite 2. Both have built-in front light. Paperwhite 3 has 300 DPI while paperwhite 2 has 216 DPI.
Power saver mode
The following file types are supported for Send to Kindle: - Microsoft Word (.DOC, .DOCX) - PDF (.PDF) - Text (.TXT) - Images (.JPG, .JPEG, .GIF, .PNG, .BMP) - Kindle Format (.AZW, .MOBI) - Other File Types (.RTF, .PRC, .PSZ)
- Browser (send web content): Chrome and Firefox (Not compatible with Firefox Quantum)
- PC or Mac (send documentations)
- Email (send documentations)
- Android (send documentations)
Question: how to do it in R?
Kinstant - the start page for Kindle's web browser
Removing Kindle User's Guide
https://www.mobileread.com/forums/showthread.php?t=288690. Change the selector at the top left of the library screen from "ALL" to "DOWNLOADED". The "ALL" option shows you all the items in your Cloud library; "DOWNLOADED" shows you just what's currently on the device.
- https://www.azwsoft.com/?c=OBJ-KDR-1 (paid with free trial 30 days)
Amazon Kindle Fire Tablet
- Fire Tablet Tool makes hacking Amazon’s 2017 tablets easier
- Install Google Play & Remove Ads on an Amazon Fire Tablet Without Root
Panasonic Troubleshooting - Error Message "No Link to base" Menu - Initial setting - Registration. Follow the screen to press the 'Locator' on the base for 5 seconds and then press 'OK' on the handset. Done. ✅ See also p35 on the manual for registering a handset.
Best headphones: Our top picks for personal listening. Over-the-ear headphones explained, Wireless headphones explained, Noise-cancelling technologies explained.
- Bose QuietComfort 35 .52 lb
- Bose SoundLink .43 lb
- Sony WH-1000XM2 .61 lb
- Sony - H900N .64 lb. Official website
- Audio-Technica ATH-M50x .63 lb
- TaoTronics Active Noise Cancelling Bluetooth Headphones tt-bh22 .48 lb
- Sennheiser HD 4.40 .49 lb
- Sennheiser PXC 550 .49 lb
- Avantree Audition Pro - aptX LL .43 lb
- 3M Worktunes Wireless Hearing Protection with Bluetooth Technology and AM/FM Radio 1.3 pounds
You Really Can Charge Your Phone With a 9 Volt Battery
From Lifehacker. A car charger is required. Line up your 9 volt battery, with the big (negative) battery terminal on the spring, and the positive (smaller) terminal touching the button in the center of the car charger.
USB voltage meter
- How to measure and compare the capacity (watt hours) of a powerbank or https://www.tp-link.com/us/faq-741.html
- Measure: 6320 mAh * 4.94 V / 1000 = 31.22 Watt hours
- Claimed: 10050 mAh * 3.7 V / 1000 = 37.2 Watt hours
- Raspberry Pi zero w + Camera module. After 169 hours, the USB voltage shows 13539 mAh and Kill-a-watt shows 0.18 kWh.
- Raspberry Pi 2B + ethernet + HDMI + keyboard USB dongle + Wifi USB. USB voltage meter shows it draws 0.33A=330 mA; see also the official documentation from the FAQs: What are the power requirements?
- 6000 mAh * 3.7 / 4.94 = 4494 mAh
- After 2 hours, USB voltage meter shows 645 mAh (~2*330 mA). So I guess my 6000mAh power bank can last 14 hours in total.
- Raspberry Pi Power Measurements
- How long would an 11,000mA power bank power a raspberry pi?
- Power Consumption Rate of Pi2 on USB Battery Bank? calculation.
- Battery amp-hour, watt-hour and C rating tutorial (Video). A 2000 mAh or 2Ah battery means it can supply 2A for 1 hour (or 1A for 2 hours or 4A for 0.5 hour, there is a max Amp it can supply and it will be very hot if we push it to the limit) until the battery ran out of battery.
- Capacity (in Ah) / Load (in A) = battery in hour (in h)
- Volts (V) * Amp-hours (Ah) = Watt-hours (Wh), amount of energy. For example, 1.2V * 2Ah = 2.4 Wh, 9.6V * 2Ah = 19.2 Wh.
- Volts, Amps and Watts explained (Video)
- Amps * Volts = Watts (power/energy)
- Amps (current) is like how much water is flowing.
- Volts (voltage) is kinda like water pressure.
- Voltage = Current x Resistance
Kill A Watt P3
Note: click the 3rd button to switch between Watt and VA; similarly for the 4th and 5th button.
Volt --- Amp --- Watt/VA --- Hz/PF --- kWH/Hour
The relation of Volt-Amp-Watt-VA-PF are
1. VA = Volts x Amps 2. Watt = VA x Power factor (OR W = VA x PF)
For example, if the apparent power is 3000 VA and the power factor is 0.8, the real power is 3000x0.8=2400 Watt.
From the Pepco company, my bill is $530.40 (total usage is 4097 KWh) from 11/27/2014 to 12/16/2014.
Delivery Charges: ================= Distribution services: Customer charge: = 7.39 Energy charge, first 800 KWH x 0.0272 = 21.76 Energe Charge, next 3297 Kwh x 0.0272 = 89.71 Franchise tax (delivery) at .00062 per kWH = 2.54 Universal service charge 0.36 MD Environmental surchage .00015 per kWH = 0.61 EmPower MD charge res .0037 per kWh = 15.16 Gross Receipts tax 2.0408% = 2.81 Montgomery city energy tax res .01131 per kWH = 46.34 Administrativ credit res .0002912 per kWH = 1.19- ========================================================== Subtotal = 185.74 Supply charges: =============== Generation services: Energy Charge 4097 kwh x 0.07732 = 316.78 Procumental cost adj res .0005936 per kwh = 2.43- Transmission services: Energy charge 4097 kwh x .007250 = 29.70 gross receipts tax at 2.0408% = 0.61 ========================================================== Subtotal = 344.66 Total = 530.40
So it looks like the charge per kWH is about .0272 + .0037 + .01131 + .07732 + .00725 = 0.12678.
- On my home server (idle most of time) with a cpu of AMD Phenom(tm) II X6 1055T Processor, it consumes 1.75kWh in 24 hours. Instantly Kill-a-watt shows 70+ Watt from the machine which makes sense (24 * 70 ~ 1750). So the yearly cost of leaving the machine on is about 1.75 * 365 * 0.12678 = 81. For HP chromebox (Intel Celeron 2955U Processor 1.4 GHz), the yearly cost is about 0.2 * 365 * 0.12678 = $9.25.
- For Pi-top (+ Raspberry Pi 3), 11 hours is 0.06 kWh. 0.07 amp. 0.59 PF. 9 VA and 5 Watt (120v * 0.07amp * .59PF = 9VA * .59PF). For 24 hours, it consumes ~0.14kWh (vs 1.75 kWh in Phenom).
- For raspberry pi zero w + Waveshare 2.7 e-paper running the clock weather application, it used up 6000 mAh @ 3.7A (4494mAH @ 4.94V)portable battery in 28 hours 40 minutes. 4494/28.67 = 156. Cf How much power does Pi Zero W use?.
- For Intel NUC7PJYH, 24 hours is 0.09 kWh (including suspend after 2 hours). The idle power is 4W and using browser to watch Youtube is 9W.
- For ASUS chromebox CN60 (i3-4010U) running the latest ChromeOS, 24 hours is 0.06 kWh.
- See http://www.howtogeek.com/234222/why-you-never-need-to-put-your-apple-tv-or-other-modern-devices-to-sleep/ for explanation about Apple TV and Fire TV case. For example, 2.1 watts of power /1000 * 24 * 365 * $0.125 = $2.29 per year. For Roku Premiere+, .07/36*24 * 365 * $0.125 = $2.2 per year.
- UDOO 4W, SainSmart 9" LCD 3W.
- How many watts of power does the latest MacBook Pro use?. My 2018 macbook pro uses 50+ Watt.
How to Calculate Kilowatt Hours
- What is a watt vs a watt-hour?. A watt (W) is a unit of power, while a watt-hour (Wh) is a unit of energy. Watts = Watt-Hours / Hours. The number of watts is a good measure of how much power your panels will produce in a moment of time. Watt-hours provides a measure of how much energy you’ll use in a provided period of time (hour).
- Residential Electricity Rates & Consumption in Maryland
SSD and HDD power comparison
How Much Electricity Each Item in Your House Uses
- Some calculation. The solar panel is measured by Watt & Volt but the battery is measured by Wh.
- Renogy 100 Watts 12 Volts Monocrystalline Solar Starter Kit
- Grape Solar 100W Polycrystalline Solar Panel (include watt calculation), converter 100watts 12volts DC to 10watts 120volts AC? and Home depot
- Environment concern
Portable battery != Jump starter
- Honda by Jackery HLS 290 Portable Lithium Battery Mobile Power Station. Capacity: 292Wh. Working time = 292Wh* 0.85 / operating power of your device.
- PAXCESS Portable Power Station, 280Watt Solar Electric Generator. Capacity: 250Wh.
- Jump Starter
Login: initpass See FAQ
Toner: TN760 - 3000 pages, $75. 3rd party.
Laser Engraving Machine
- NEJE 300mW Mini DIY Laser Engraving Machine Picture Logo CNC Laser Printer and 500mW version.
- mdrawBot and 500mW laser engraver
- Laser cube 2.0 (100mw laser diodes). Laser engraver from makeblock.cc (500mw laser engraver).
Make your own laptop screen for Raspberry Pi
- Paperlike monitor - Windows is supported. For other OS, uses VirtualBox.
- Second-Gen Dasung Paperlike E-ink Monitor May 2016
- Paperlike Pro review. 40 refresh frame rate on HDMI.
- Not-eReader: First E-ink Mobile-Phone Monitor
Kindle DX as an external monitor
Traveler: Ultimate Distraction-Free Writing Tool
Boox Note Plus
- http://www.boox.com/boox-note-plus/, Download
- https://www.amazon.com/BOOX-Upgraded-Note-eReader-Android/dp/B07GZM5M98 $569
- https://goodereader.com/blog/electronic-readers/onyx-boox-note-plus-10-3-inch-e-reader-review, $529
- 13.3″ Onyx Boox Max2 vs 10.3″ Boox Note Comparison Review
Hardware spec (page 97 of the manual): 13.3 inch & 2200 x 1650 pixel, CPU is 1GZ, Ram is 1GB LPDDR2, Android 4.0.4, 16GB storage, 1.21 lbs (ipad 9.7in 2017 is 1.03 lbs). Very comfortable when I use it to read technical papers. It does not have front light, unfortunately. Shipping took about 2.5 weeks.
The manual is written in simplified Chinese only:) It is lightweight. Writing on the ereader is OK. Got it from banggood.com.
- MAX Discussion
- F-Droid as an replacement to Google Play Store
- Discussion from mobileread.com
- E Ink Carta and Carta HD displays support Regal waveform technology, which reduces the need for page refreshes
Onyx Boox Max Carta vs Onyx Boox MAX2
Max2 has a micro HDMI port.
Boox as a Second Monitor
- https://youtu.be/KUO-nt6WlvA (mention quality mode and responsive mode)
- https://youtu.be/lWAsfZTUrJs (include an instruction by using tightVNC on Mac/Windows/Linux platforms)
- https://youtu.be/aZCjYU9msuA Boox i86 - VNC session on EPD display
- Discussion from mobileread.com
- https://github.com/nahtethan/dxg-display/blob/master/BOOXen.md USB solution
Boox and SSH terminal
I found using Max Carta to do work on a terminal is OK.
First go to the Play Store to download an SSH client. I am using JuiceSSH.
We can adjust font size and the theme (white as the background). Even you have connected to a host, you can still use the volume +/- to increate/decrease font size on-the-fly.
You cannot rotate the screen however.
I am using a bluetooth keyboard. If I don't use the keyboard for a couple of minutes, it'll take a few seconds for the device to respond to my typing.
When I use nano, the color syntax highlight is not good. So I use nano -Ynone FILENAME to disable the syntax highlight.
Airdroid works for transferring files between Boox and computers in the same network.
Boox and remote desktop
Note the the device has locked to rotate the screen (i.e. the screen rotation app from Play Store does not work)
When testing to connect to a Windows Desktop
- Microsoft remote desktop does rotate the screen but it does not respond to my clicking
- bVNC does not rotate the screen
Open html files
If I made a copy of a website (efficient R programming for example), then use Boox's default browser to open the html file, some links do not work.
Open epub files
- FBReader: no TOC
- NEO Reader v2.0: *TOC works*
- Onyx Neo Reader: format is OK, but not TOC
- OReader: no TOC
Open pdf files
- Neo Reader v2.0: TOC & search work! We can use the 'Crop Page' function to remove blank space on sides.
- Onyx Neo Reader: no TOC
PDF format has an advantage over epub: mathematical notation is guaranteed.
Notes we created cannot be seen from Storage > sdcard > note directly. In order for the notes to be seen there (so we can copy them to computers through AirDroid), we need to click on each note and choose the gear icon and pick "Export the current page" or "Export all pages".
The default music player works fine. I also like VLC downloaded from Play Store.
Date Automatic date & time: uncheck
- Sleep: 30 seconds
- Power off timeout: 60 minutes
- Network Inactivity Timeout: 15 minutes
microSD card To eject it, go to Settings > Storage > Unmount SD card.
Reset the firmware Settings > Privacy > Factory data reset.
- Open the last read document: uncheck
- Homepage preference: Show new added books
- Show books' tittles instead of their names in library: uncheck
Language Hacker's Keyboard
- USB debuggin
- Manage apps
DRM Setting Adobe ID
- Battery level
- IP address
- Model number: MaxCarta
- Build number: 2017-04-28_18-25_1.8.2_e4efe5. There is a button to "Check update from local storage".
Android version 4.0.4
- Device Info-HW
- Hacker's Keyboard
- JuiceSSH. For some reason, I cannot connect to my bluetooth keyboard. So the app is not useful.
- VLC. It provides a loop function. However like the default 'Music' player, when I play a music, it will have a hiccup every few seconds.
Conclusion: it is best to use the device for viewing documents only.
Not compatible with Boox Max Carta Android 4.0.4. According to this, Android 4.1 is required. This source said the app is best supported with an android device of version 4.4. Android 4.4 seems to be required for other Android apps to work according to Good e-Reader.
Regular Amazon Kindle app. Not responding.
I have a Kobo Aura HD. The touch screen is controlled by infrared (like the Nook Simple Touch, no requiring electrical conductivity), not capacitive or resistive technologies. Even a paper or an eraser works on the touch screen. Its screen is 6.8 inch, 1440 x 1080-pixel display with 265 dpi. The brightness is 326 lux. The built-in front light comes the light technology from the ComfortLight. It directs light at the page and boasts an even distribution across the display. The microSD slot can add up to 32GB to the built-in 4GB of storage. The exact model is not on sale now because it is replaced by H2O.
Kobo Wifi Weather Forecast
The pdf program is not quite useful for scientific papers.
- Go to here and download <KBStartMenu_07inclUp4.zip>. Extract the folder kbmenupngs (it contains png files) and put it to the root folder of Kobo. Also put KoboRoot.tgz to .kobo hidden directory (putting it onto .adds won't work). Reject and reboot.
- Download <koreader-kobo-arm-linux-gnueabihf-v2014.04> from v2014.04-stable github page. Put koreader folder in the .kobo hidden directory. Ignore the png file and KoboRoot.tgz file there. Reject and reboot.
If something goes wrong, we can go to Settings -> Device information -> Factory reset to reset the system. It can also download the update after the wifi configuration is set up.
When you update koreader, it should be sufficient to extract the koreader folder, without KoboRoot.tgz - that one is needed to add the launcher.
Standby does not work out of box. See http://www.mobileread.com/forums/showthread.php?t=216960&page=85. That is, run
nano -c /media/brb/KOBOeReader/.kobo/koreader/frontend/ui/uimanager.lua
and change the Standby value from 1 to 4 and suspend function call from 0.5 to 2. The standby problem is resolved.
Battery always 100% (too good to be true, I have not used the ereader for a while). http://www.mobileread.com/forums/showthread.php?t=220912. It`ll take care of itself after a few charge cycles.
.kobo folder after reset
After I run factory reset on the device (and plug in it to my computer), I see the device only has 3 hidden directories
[email protected]:~$ ls -la /media/brb/KOBOeReader/ total 20 drwx------ 5 brb brb 4096 Dec 31 1969 . drwxr-x---+ 4 brb root 4096 Oct 11 10:22 .. drwx------ 2 brb brb 4096 Oct 11 2015 .adobe-digital-editions drwx------ 7 brb brb 4096 Oct 11 2015 .kobo drwx------ 8 brb brb 4096 Oct 11 2015 .kobo-images [email protected]:~$ ls -la /media/brb/KOBOeReader/.kobo total 152 drwx------ 7 brb brb 4096 Oct 11 2015 . drwx------ 5 brb brb 4096 Dec 31 1969 .. -rw-r--r-- 1 brb brb 25 Oct 11 2015 affiliate.conf drwx------ 2 brb brb 4096 Oct 11 2015 certificates -rw-r--r-- 1 brb brb 76 Oct 11 2015 device.salt.conf drwx------ 2 brb brb 4096 Oct 11 2015 dict drwx------ 2 brb brb 4096 Oct 11 2015 kepub drwx------ 2 brb brb 4096 Oct 11 2015 Kobo -rw-r--r-- 1 brb brb 110592 Oct 11 2015 KoboReader.sqlite drwx------ 6 brb brb 4096 Feb 28 2013 slideshow -rw-r--r-- 1 brb brb 3298 Oct 11 2015 Trolltech.conf -rw-r--r-- 1 brb brb 84 Oct 11 2015 version [email protected]:~$ ls -la /media/brb/KOBOeReader/.kobo-images/ total 32 drwx------ 8 brb brb 4096 Oct 11 2015 . drwx------ 5 brb brb 4096 Dec 31 1969 .. drwx------ 3 brb brb 4096 Oct 11 2015 132 drwx------ 3 brb brb 4096 Oct 11 2015 18 drwx------ 3 brb brb 4096 Oct 11 2015 213 drwx------ 3 brb brb 4096 Oct 11 2015 233 drwx------ 3 brb brb 4096 Oct 11 2015 66 drwx------ 3 brb brb 4096 Oct 11 2015 70
KOReader supports any Stardict format dictionaries. To use that, we need to download and put the dictionary 'folder' in the right place (.kobo/koreader/data/dict) of the Kobo ereader.
I tried two dictionaries (Longman Dictionary of Contemporary English and cdict-big5 dictionary) from http://abloz.com/huzheng/stardict-dic/. And they work fine.
Turn your Kobo into a Debian Linux tablet
Power over Ethernet (PoE)
- TP-LINK TL-POE10R Gigabit PoE Injector or Splitter
- p56 of https://www.raspberrypi.org/magpi-issues/MagPi45.pdf
Some devices powered by PoE include VoIP phone, IP camera, wireless access point. router.
Type-C Multi-Port Adapter
Trendent USB to ethernet adapter
ASIX AX88772A. The windows driver can be found on axix.com.tw. The one from Trendent website does not work.
USB OTG adapter
Magnetic Braided USB Charging Cable
How to Crimp Your Own Custom Ethernet Cables of Any Length
How to park your car on a hill
When parking your car on a hill, put the car in neutral, set the emergency brake, then put the car in park (or in gear). This puts the weight of the car on the emergency brake rather than the transmission and can extend the life of your transmission.
- Roku Premiere+ (2016 model, model # 4630R, 5th generation) 4K video, HDR support, AC dual band, ethernet & microSD port and a wifi direct remote w/ a headphone jack.
- Re-pair the remote: Press the small button beneath the battery. Hold it for 3 seconds while positioning the remote next to the Roku.
- 20 Roku Hacks To Make Your Life Easier Oct 2018
- NewsOn app to watch local TV. I can watch WUSA9 (CBS) and a few. But they are not 'live' though it's the same day news.
- Roku iOS/Android app allows to use our bluetooth headphone for listening; see private listening.
- Prioritize by Service
- Prioritize by Interface
- Prioritize by Device with IP Addresses
- Prioritize by Device with MAC Addresses
Wifi and health
Wifi and Microwaves
Logitech Unifying Software
ChromeOS version works fine.
Best bluetooth mouse
Mouse Acceleration vs Sensitivity
Sensitivity/Speed is how far you have to move the mouse to move the pointer a particular distance. A high speed means that very small movements will shoot the cursor a large distance.
Acceleration is a very clever optimization. Normally, to keep precision control over the cursor (for those who need it) you need to keep the speed pretty low. But this means that if you need to get to the other side of the screen, you need to slide the mouse annoyingly far. Acceleration lets you have the best of both worlds.
What acceleration does is boost the speed temporarily when you 'flick' the mouse. So if you need to get to the other side of the screen, you can flick the mouse quickly just a short distance and the cursor will move much further. You then switch to moving more slowly to get the cursor exactly where you want it.
On Linux Mint, I can change these two settings individually. I use medium for the sensitivity and 3/4 high for acceleration.
Logitech wireless solar keyboard k750
- Best typing feeling (similar to a laptop computer).
- Solar App and download links for Windows & Mac.
One problem is there is no Num Lock and Caps indicator on the keyboard unless you have install Logitech SetPoint software (Windows & ChromeOS).
Logitech K380 Multi-Device Bluetooth Keyboard
Lenovo ThinkPad Compact USB Keyboard with TrackPoint
- https://www.amazon.com/Lenovo-ThinkPad-Compact-Keyboard-TrackPoint/dp/B00F3U4TQS USB model
- https://www.amazon.com/ThinkPad-Compact-Bluetooth-Keyboard-TrackPoint/dp/B00C32FWJC/ bluetooth
- Logitech C525
- Logitech C920 H.264 video compression.
A bluetooth based gadget to control a windows/android/ios device. See http://qblinks.com/support
How to Replace an Outlet That’s Controlled by a Light Switch
How to Ship Packages Without Leaving Your House
- Use a Drone Simulator to Practice Before You Buy
- Fly zone map
- How to Get an FAA Drone License As Fast As Possible
Dell PowerEdge R630 server
- http://www.dell.com/en-us/work/shop/productdetails/poweredge-r630/pe_r630_1337 and the manual
- integrated Dell Remote Access Controller (iDRAC)
- iDrac 8 manuals/videos
- Different packages of iDRAC (Express is included)
- How to install and configure iDRAC Service Module? This is to deal with the error when I try to use virtual media (iso file) to install a new OS. RAC0690: The iDRAC Service Module is not installed on the operating system of the server.
- RAID configuration
- /boot, recommended size at least 1 GiB. Unlike other mount points, using an LVM volume for /boot is not possible - /boot must be located on a separate disk partition.
- swap. If <=2 GB ram, give 2*RAM for swap. If 2<RAM<=8, gives 1*RAM for swap. If RAM >=8, gives 4G to 0.5*RAM for swap.
- Dell Lifecycle Controller
- OS installation
- How to install the operating system on a Dell PowerEdge Server ? (OS deployment).
- Method 1: Using LifeCycle Controller for Supported OS. Note that the boot mode BIOS/UEFI has to be configured properly in the "System Services" settings (F2).
- Method 2: Booting directly on the OS Media.
- OS Deployment Manual Installation
- Remote OS Installation
- How to install the operating system on a Dell PowerEdge Server ? (OS deployment).
iPad 9.7 2017 (5th)
- https://www.apple.com/ipad-9.7/specs/. A9 chip, 1.84 GHz. 2GB ram.
Rocketbook Erasable, Reusable Wirebound Notebook - Letter Size
- Should I Remove My Laptop Battery To Increase its Life? It really depends on the voltage cutoff of the device in question.
- The Formula for Estimating Laptop Battery Life. Just divide your computer battery’s watt-hours by your estimated wattage. The result is the number of hours you can expect your battery to last. Your expected wattage varies depending on the task you’re performing. Gaming will use between 40 and 60 watts, watching video will consume 15 to 30 watts, and web browsing will eat 10 to 15 watts.
- Google: At what voltage are alkalines considered dead? It really depends on the voltage cutoff of the device in question.
- 9V battery Low Voltage?
- ExpertPower 12V 7 Amp EXP1270 Rechargeable Lead Acid Battery. I use it to replace the battery in the Verizon fios box.
- The beep sounds comes every 15 minutes.
- 12V 14.4V 1A Portable Lead Acid Battery Smart Charger
- It seems it is not necessary to buy a charging unit in order to charge the battery. If low battery light is on, it probably means it is time to replace the battery (cannot hold the power).
- How many hours would battery last: A 6 watt load on 12v battery corresponds to a 0.5 amp discharge rate. Since the battery is rated at 7AH(7 amp-hours), 7AH/0.5A = 14 HOURS period. However, the battery voltage will decrease during the discharge cycle.
- 12 volts * 7 amps will power 84 watts.
- Verizon Battery Backup Unit (BBU) Information
- Sealed lead acid batteries can only be charged and discharged 300 times at the most.
- Verizon Optical Network Terminal (ONT)
- Casio Men's MRW-S300H-1BVCF: Rechargeable battery life is about 10 years
- Casio Women's LA20WH-1ACF : CR1616 3V, 5 years
Used in PC, car remote, ...
Govee Wi-Fi Temperature and Humidity Monitor
Google voice & Obihai
Outgoing calls stopped working on GV TCP connection to 18.104.22.168 failed. Dec 2017.